Device for Locking Electrical Devices, in Particular Power Tools, with Battery Packs for Power Supply

ABSTRACT

The invention relates to a device for locking electric appliances ( 2 ) with battery packs ( 4 ) for power supply, whereby the electric appliances ( 2 ) comprise a displaceable bolt ( 14; 36; 38; 40; 42 ) and the battery packs ( 4 ) comprise at least two recesses ( 24, 26 ) and the recesses ( 24, 26 ) are arranged serially behind each other in the direction of a relative movement of the electric appliance ( 2 ) and battery pack ( 4 ) and, after locking, the bolt ( 14; 36; 38; 40; 42 ) engages in one of the recesses ( 24, 26 ). According to the invention, the recesses ( 24, 26 ) have a different form or different dimensions or are offset perpendicular to the movement direction and that for various combinations of electric appliance ( 2 ) and battery pack ( 4 ), the form, the dimensions and/or offset of the recesses ( 24, 26 ) are matched to the form, dimensions and position of the bolt ( 14; 36; 38; 40; 42 ), such that the bolt ( 14; 36; 38; 40; 42 ) engages either only in the front recess ( 24 ), only in the rear recess ( 26 ), or sequentially firstly in the front and then in the rear recess ( 24, 26 ).

The invention relates to a device for locking electrical devices, inparticular power tools, with battery packs for power supply, asgenerically defined by the preamble to claim 1, and to a battery packand an electrical device as generically defined by the preambles toclaims 9 and 10, respectively. The term “battery pack” used here isintended also to include battery packs that contain rechargeablebatteries (also known as accus).

PRIOR ART

For securing a battery pack acting as a power supply, large, heavy powertools that are guided by hand, such as drill hammers or the like, inparticular have a device of the type defined above, with a two-stagelocking means known as a double locking means. In older devices, alocking bar is provided in a housing of the electrical device and ismovable counter to the force of a spring. The locking bar enterssuccessively into engagement with two detent grooves in the batterypack, which are cut out one after the other, in the direction of therelative motion during the attachment of the battery pack, in a part ofthe battery pack located diametrically opposite the locking bar. Thefront detent groove, with which the locking bar enters into engagementfirst as the battery pack is being attached, serves there to connect thebattery pack to the housing of the power tool in such a way that it canno longer be release from the housing, unless the locking bar isactuated manually. This assures that for transporting the power tool,the battery pack is fixed in the power tool housing so that it issecured against falling out, but as yet without contact between theterminals of the battery pack and of the power tool. This contact is notestablished until the battery pack is thrust by the user far enough intothe power tool housing that the locking bar engages the rear detentgroove, after having been forced out of the front detent grooveautomatically at the onset of this insertion motion.

On the one hand, manufacturers of various battery-operated electricaldevices want not only to embody the battery packs such that they can beused in all kinds of devices, but also to largely standardize thedevices in terms of their interface with the battery pack, by usingessentially the same locking mechanism in all kinds of devices. On theother hand, a double locking means is usually not wanted in all of thesekinds of devices, for example because a double locking means isunnecessary in devices with small, lightweight battery packs, or becausein some devices the customer does not expect a double locking means andhence mistakenly already assumes that proper contact between theelectrical device or the battery pack is established upon engagement ofthe locking bar or locking bars with the front detent groove or thedetent grooves.

ADVANTAGES OF THE INVENTION

At the place where the locking bar, including the actuation device,together hereinafter called the locking mechanism, is conventionallylocated in the in the electrical device, while the recesses for thelocking bar are provided in the battery pack, the device of theinvention having the characteristics recited in claim 1 and the batterypack having the characteristics recited in claim 9 have the advantagethat when identical battery packs and a locking mechanism with asuitable embodied or positioned locking bar are used, the capability iscreated of selectively providing a single or a double locking means, orfor reasons of space, for instance, of performing the final lockingselectively with the front recess or with the rear recess. Anotheradvantage is that except from the locking bar itself or its installedposition in the device, the locking mechanism can be standardized in allkinds of devices.

With the device of the invention it is for instance possible, in acombination of an electrical device and a battery pack, to make thecontact between the battery pack and a current circuit of a consumer ofthe electrical device only upon engagement of the locking bar with therear recess, while in a different combination of an electrical deviceand a battery pack, the contact is already made upon engagement of thelocking bar with the front recess.

A different shape of the recesses is expediently attained by providing aprotrusion in one of the recesses, preferably in the form of a ribdividing the recess, which makes it possible for a locking bar to engagea cutout, preferably a slot that receives the rib, that is complementarywith the protrusion, while the engagement of a locking bar without acutout of this kind is prevented. The recesses themselves areexpediently embodied as detent grooves, as in the prior art.

If in a combination of an electrical device and a battery pack, thepossibility of a double locking means is to be provided, and if in twoother combinations of an electrical device and a battery pack with asingle locking means the locking is to be made in the one case uponengagement of the locking bar with the front recess and in the othercase upon engagement of the locking bar with the rear recess, then in apreferred embodiment of the invention it can be provided that tworecesses of different shape and different dimensions, or two recessesoffset from one another and of different shape or different dimensions,can be combined with one another.

Furthermore, it is also possible to provided more than two recesses,located one after the other in the relative motion upon locking, ofwhich each enters into engagement with the locking bar of a differentelectrical device, in order to accomplish the locking; two of therecesses at a time may be jointly operative in pairs, to accomplish adouble locking.

The locking bars are preferably provided in the electrical devices, andthe recesses in the battery packs, but a reverse arrangement is alsofundamentally possible.

DRAWINGS

The invention will be described in further detail below in terms of twoexemplary embodiments in conjunction with the drawings. Shown are:

FIG. 1: a cross-sectional view of part of a combination of an electricaldevice and a battery pack with double locking, after the battery packhas been partially introduced;

FIG. 2, a view corresponding to FIG. 1, but after the battery pack hasbeen completely introduced;

FIG. 3: an exploded view in perspective, partly cut away, of one side ofthe battery pack in conjunction with the locking bar of the electricaldevice of FIGS. 1 and 2;

FIG. 4: a view corresponding to FIG. 3, but in conjunction with thelocking bar of an electrical device without double locking;

FIG. 5: a simplified top view of a similar battery pack in conjunctionwith three locking bars, shown in perspective, of different electricaldevices.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

In a combination, shown only in part in the drawing, of an electricaldevice 2, such as a hand-guided electrical power tool, and a batterypack 4 serving as a power supply for the electrical device 2, theelectrical device 2 conventionally has a seat 6 for the battery pack 4;the battery pack is thrust into this seat in the direction of the arrowA, on the one hand for connecting the battery pack securely to theelectrical device 2 and on the other for making an electricallyconductive connection between terminal contacts 8 of batteries in thebattery pack 4 and a current circuit of the consumer (not shown) of theelectrical device 2.

For restraining the battery pack 4 in the seat 6, a housing 10 of theelectrical device 2 has a locking mechanism 12, which when the batterypack 4 is introduced into the seat 6 brings about locking of the batterypack to the housing 10. The locking mechanism 12 includes a plurality oflocking bars, only of which is shown at 14. The locking bar 14 isrigidly connected to an actuation slide 16, which protrudes outward pastthe housing 10, and is displaceable counter to the force of a spring 18in a guide 20 cut out of the housing 10. The guide 20 is open toward theseat 6 in the direction of motion of the locking bar 14, so that a freeface end 22 of the locking bar protrudes into the seat 6 when the slide16 is not actuated. The face end 22 is beveled on its side toward theopening of the seat 6, so that when the battery pack 4 is introduced,the locking bar 14 is pressed into the guide 20, counter to the force ofthe spring 18.

The battery pack 4 is also provided, in its side toward the guide 20,with two detent grooves 24 and 26, which the face end 22 of the lockingbar 14 automatically engages in succession when the battery pack 4, onbeing introduced into the seat 4, reaches the position shown in FIG. 1and the position shown in FIG. 2, respectively.

The front detent groove 24, as viewed in the direction of motion of thebattery pack upon insertion or locking, serves to lock the battery pack4 to the housing 10 in the position shown in FIG. 1, to prevent thebattery pack 4 from falling out, for instance while being transported.In this position, the terminal contacts 8 of the battery pack 4 do notyet engage associated receiving bushes (not visible) of the electricaldevice 2 that are provided in a bottom 28 of the seat 6, so that as yetthere is still no electrical connection between the batteries of thebattery pack and the current circuit of the consumer of the electricaldevice 2. The rear detent groove 26 serves to lock the battery pack 4 tothe housing 10 in the position shown in FIG. 2, in which, because of theengagement of the terminal contacts 8 with the receiving bushes of theelectrical device 2, an electrical contact between the batteries and theelectrical device 2 does exist. The two grooves 24 and 26 have across-sectional shape adapted to the cross-sectional shape of the frontface end 22 of the locking bar 14, and they are somewhat wider than thelocking bar 14.

As best shown in FIG. 3, the face end 22 of the locking bar 14 thatenters into engagement with the grooves 24, 26 is provided with acentral slot 30, which extends, with constant cross-sectionaldimensions, through the face end 22 in the direction of motion of thebattery pack 4. Of the two grooves 24 and 26, the rear groove 26 extendswith constant cross-sectional dimensions over its entire width, whilethe front groove 24, with the same width in the middle, is interruptedby a rib 32 that extends in the direction of motion of the battery pack.The rib 32 is located diametrically opposite the slot 30 in the lockingbar 14 and is somewhat narrower than this slot, so that the face end 22of the locking bar 14 can engage the first and the second grooves 24, 26unhindered, in order to enable the double locking between the electricaldevice 2 and the battery pack 4 as described in conjunction with FIGS. 1and 2.

While the battery pack 4 shown in FIG. 4 is identical to the batterypack of FIGS. 1-3, in FIG. 4 the front face end 34 of a locking bar 36of an otherwise identically or similarly constructed locking mechanism12 of a different electrical device (not shown) is not provided with theslot 30, so that it moves past the front groove 24 and enters intoengagement with only the rear groove 26. The locking between the batterypack therefore takes place in the form of a single locking means, inwhich mechanical locking is established only together with theelectrical contact in the position shown in FIG. 2 of the battery pack4.

In a distinction from the battery pack 4 described earlier above, thetwo grooves 24 and 26 of the battery pack 4 shown in a top view in FIG.5 additionally have a different length transversely to the direction ofmotion of the battery pack, and the rear groove 26 is shorter than thefront groove 24 that is interrupted by the rib 32. As a result, it isattained that the locking mechanism 12 of an electrical device, for thesake of double locking, enters into engagement with both grooves 24 and26, if, as is the case for the center locking bar 38 in FIG. 5, thefront face end 22 of the locking bar 38 is somewhat narrower than thegroove 26 and has a slot 30, diametrically opposite the rib 32 of thegroove 24, for receiving the rib 32. Conversely, if the front face end22 is wider than the groove 26 and has a slot 28 diametrically oppositethe rib 30 of the groove 24, as in the case of the upper locking bar 40in FIG. 5, the locking bar enters into engagement only with the frontgroove 24, while only if its front face end 22 is somewhat narrower thanthe groove 26 but is not provided with a slot 28, as in the case of thelower locking bar 42 in FIG. 5, does it enter into engagement with therear groove 26. In both of these last two cases, upon engagement of thelocking bar 40 or 42, not only the mechanical locking but also theelectrical contact between the batteries of the battery pack 4 and thecurrent circuit of the consumer of the electrical device areestablished.

1. A device for locking electrical devices, in particular power tools,with battery packs for power supply, in which the electrical deviceshave one movable locking bar and the battery packs have at least tworecesses, or vice versa, and upon locking, the recesses are located oneafter the other in the direction of a relative motion between theelectrical device and the battery pack, and after locking, the lockingbar engages one of the recesses, characterized in that the recesses (24,26) are differently shaped or of different dimensions or are offsettransversely to the direction of motion; and that in differentcombinations of electrical devices (2) and battery packs (4), the shape,dimensions and/or offset of the recesses (24, 26) are each adapted tothe shape, dimensions or position of the locking bar (14; 36; 38; 40;42) in such a way that the locking bar (14; 36; 38; 40; 42) engageseither only the front recess (24) or only the rear recess (26) orsuccessively the front recess and then the rear recess (24, 26,respectively).
 2. The device as defined by claim 1, characterized inthat in a combination of an electrical device (2) and battery pack (4),the contact between batteries of the battery pack (4) and a currentcircuit of a consumer of the electrical device (2) is made uponengagement of the locking bar (42) with the rear recess (25) and in adifferent combination of an electrical device (2) and battery pack (4)is made upon engagement of the locking bar (40) with the front recess(24).
 3. The device as defined by claim 1, characterized in thatprotruding into one of the recesses (24) is a protrusion (32), whichpermits the engagement of a locking bar (14; 38; 40) with a cutout (30)that receives the protrusion (32) and prevents the engagement of alocking bar (36; 42) without such a cutout (30).
 4. The device asdefined by claim 3, characterized in that the bp is a rib (32) in therecess (24), and the cutout is a slot (30) in the locking bar (14; 38;40).
 5. The device as defined by claim 1, characterized in that therecesses (24, 26, FIG. 5) are differently shaped and of differentdimensions.
 6. The device as defined by claim 1, characterized in thatthe recesses are differently shaped and are offset from one another. 7.The device as defined by claim 1, characterized in that the recesses areof different dimensions and are offset from one another.
 8. The deviceas defined by claim 1, characterized in that the locking bars (14; 36;38; 40; 42) are located in the electrical devices (2), and the recesses(24, 26) are located in the battery packs (4).
 9. A battery pack forlocking to an electrical device, in particular a power tool, whichincludes a movable locking bar, and the battery pack has at least tworecesses that upon locking are located one after the other in therelative motion between the electrical device and the battery pack,characterized in that the recesses (24, 26) are differently shaped or ofdifferent dimensions or are offset from one another transversely to thedirection of motion.
 10. An electrical device, in particular a powertool, for locking with a battery pack which includes a movable lockingbar, and the electrical device has at least two recesses that uponlocking are located one after the other in the relative motion betweenthe electrical device and the battery pack, characterized in that therecesses (24, 26) are differently shaped or of different dimensions orare offset from one another transversely to the direction of motion.